How Time Zones May Affect Cancer Risk

April 3, 2017

Where you live within your time zone could be associated with a slightly increased risk of developing certain cancers that have been linked to disruptions to the biological clock, a new study suggests.

People’s biological clocks can become out of whack — which scientists call “circadian disruption” — if they work the night shift, for example. Such disruptions have been linked to an increased cancer risk in shift workers, said Dr. Neil Caporaso, an epidemiologist at the National Cancer Institute and the lead author of the study.

But the disruptions that shift workers experience in circadian rhythms are major, because they switch from working during the day to working at night. Caporaso and his team were curious about whether smaller, subtler disruptions to the biological clock could also have an effect on people’s cancer risk. [10 Do’s and Don’ts to Reduce Your Risk of Cancer]

Indeed, most people experience small disruptions in their circadian rhythm in the form of social jet lag, Caporaso told Live Science. Social jet lag is commonly thought of as getting up at the same time during the week, and then sleeping in on the weekend when you don’t need to get up early for work, he said.